Moisture-dependent physical properties of Opeaburoo and Abontem maize varieties during drying

This study specifically seeks to find out the changes in moisture content (MC) on two maize varieties (Opeaburoo and Abontem) in relation to designated physical attributes during drying. Four designated MC within a range of 22.3 to 12.8% wb for Opeaburoo and 21.5 to 12.3% wb for Abontem were used. The mean length, width and thickness dimensions reduced from 12.67 to 12.54 mm, 9.19 to 9.12 mm, and 4.58 to 4.51 mm, respectively for Opeaburoo and 11.74 to 10.57 mm, 8.69 to 8.10 mm and 5.43 to 4.79 mm, respectively for Abontem with respect to decrease in moisture content. The symmetrical average diameter, surface area, thousand grain mass and angle of repose also reduced from 8.11 to 8.02 mm, 206.4 to 204.66 mm2, 340.06 to 288.28 g and 28.77 to 22.10°, respectively for Opeaburoo and that of Abontem also recorded similar trend of reduction. Average values for volume lessened from 278.82 to 270.10 mm3 and 290.10 to 214.76 mm3 for Opeaburoo and Abontem, respectively. A non-linear regression equation was found for volume, sphericity and bulk densities in relationship with moisture contents for both varieties. A linear decrease in coefficient of friction with decreasing moisture contents were observed for the three structural surfaces for both maize varieties. The maximum resistance to flow (coefficient of friction) of the grains occurred on the plywood surface. With the exception of the mean width and thickness for opeaburoo, some pairs of the means of the physical attributes for the two maize varieties studied were statistically different at the moisture content levels.   Key words: Geometric mean diameter, sphericity, coefficient of friction, Opeaburoo, Abontem.